viper 540m no siren output

Ok, so I see all these posts about dead siren outputs, but none quite fits my problem; which is this: I installed the alarm, not the remote start quite yet thats later, and got to the end. Just before connecting the siren, I tested it. All works just dandy. Lights flash, interior light stays on after ignition off and unlock. Panic function seems to function according to design. So I decided to go ahead and put in sum earplugs and hook up the siren to test it as well. The manual tells me that the wire for horn output is supposed to supply (-)500mA intermitent on arm/disarm and constant on panic mode. So, of course, my horn running 5A I hook up a relay. Nothing. I remove the relay and test the horn on straight 12v, it works just fine. So I switch the polarity of the signal, putting the horn output as power to relay coil. Nothing. The relay won't even switch. I try both directions wiring the output wire directly to the horn, and if I listen very carefully w it as positive I can hear a faint crackle from the horn. I measured the wire on panic, and it seems to supply (+)2v, instead of (-). Is this a problem w the board, or a fluke? And how can I use this wire to run a relay so I can have a horn output on panic?

I've never heard of a Viper 540m nor is any info for that model number on Directechs.com. Are you sure that is the correct model number or is it a really old system? Want to help you out by taking a look at the guide but cant find it.

You've wired your relay wrong, it's either damaged your alarm's circuit board or the factory horn relay. Check the vehicle's fuses.

no, sorry about the number, for sum reason my head was messed up that night...lol its a 5101. dont even ask where i got the 4 from. but no, its not a relay problem. and the board is fine, unless one of the ics r fried. I just rechecked the output and its 1.6v+. not enuf to drive a relay, and the current is negligible, so just a simple voltage amp wont work. I cant for the life of me figure it out. All wires are correctly connected, and theres nothing physically wrong with the board or circuitry. if the horn output was on a relay on the board, then it should be able to drive the small alarm horns, but theres no relay, all there is is the relay for the dome light that clicks, and the light flash relay. there are 5 on the board, 4 of which i have determined their purpose, cant figure out the last one, but ill bump if i figure it out.

Horn circuit blown.

It will give either 0volt or 12v+ when on, open circuit when off.

again, nothing wrong with the board. all circuits test fine. unless its one of the microprocessors is bad, but i would think that if that were the case, then nothing would work correctly when connected. It opens to 1.6v+ when the circuit is powered, it surges to just under 2v+. The panic mode is a pulse, and each time it starts, it maxes out at about 2v+. The book says -200mA, but instead of(-) its putting out (+).

you could use one of the aux outputs. they are programmable to a 30 sec timed output or for validity so as long as you press the button it will be active. only difference is it would be a constant horn sound versus a pulsing horn sound.

I'm still confused about your model number and some stuff you wrote in your original post. you said you connected the alarm part but not the remote start. A Viper 5101 is remote start with keyless entry. there arent any alarm features on this model.

yes it is a remote start, but it has horn honk for arm/disarm and a manual panic. Im not certain if it can be programmed to goto panic on door open while armed, but I got it mainly for the lock/unlock and the remote start functions. I havent hooked up the remote start yet bcuz im still trying to figure out why it wont honk the (or any) horn on arm/disarm. As soon as I get that part worked out, ima do a wire tuck and clean up under the dash a bit, then hook up the remote start. regardless if it has an "alarm" or not, the horn should still honk on arm/disarm.

and around here, even if a vehicle doesnt have an alarm, just the horn chirp and flashing light r enuf to keep ppl away from my vehicle.